diff --git a/android_connection/__init__.py b/android_connection/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/android_connection/apply_to_android.py b/android_connection/apply_to_android.py
new file mode 100644
index 000000000..8eff732d4
--- /dev/null
+++ b/android_connection/apply_to_android.py
@@ -0,0 +1,33 @@
+from pathlib import Path
+import sys
+
+
+def _require_exists(a_file: Path) -> Path:
+  if not a_file.is_file():
+    raise ValueError(f"{a_file} not found")
+  return a_file
+
+
+def _fonts_xml(android_dir: Path) -> Path:
+  return _require_exists(android_dir / "frameworks" / "base" / "data" / "fonts" / "fonts.xml")
+
+
+def _fonts_mk(android_dir: Path) -> Path:
+  return _require_exists(android_dir / "external" / "noto-fonts" / "fonts.mk")
+
+
+def _validate_android_path(android_dir: Path):
+  assert android_dir.is_dir(), f"{android_dir} should be a directory"
+  _fonts_xml(android_dir)  # just to trigger it's checks
+  _fonts_mk(android_dir)  # just to trigger it's checks
+
+
+def main():
+  if len(sys.argv) != 2:
+    raise ValueError("Must have one arg, path to an Android checkout")
+  android_dir = Path(sys.argv[1])
+  _validate_android_path(android_dir)
+
+
+if __name__ == "__main__":
+  main()
\ No newline at end of file
diff --git a/android-connection/migrate_attrs.py b/android_connection/migrate_attrs.py
similarity index 100%
rename from android-connection/migrate_attrs.py
rename to android_connection/migrate_attrs.py
diff --git a/android-connection/noto-fonts-4-android.xml b/android_connection/noto-fonts-4-android.xml
similarity index 100%
rename from android-connection/noto-fonts-4-android.xml
rename to android_connection/noto-fonts-4-android.xml
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/apply_to_android_test.py b/tests/apply_to_android_test.py
new file mode 100644
index 000000000..f7d7d88aa
--- /dev/null
+++ b/tests/apply_to_android_test.py
@@ -0,0 +1,20 @@
+from android_connection import apply_to_android
+from pathlib import Path
+import pytest
+
+
+def _testdata_dir() -> Path:
+  return Path(__file__).parent / "testdata"
+
+
+def _fake_android_dir() -> Path:
+  return _testdata_dir() / "fake_android"
+
+
+def test_apply_to_bad_dir():
+  with pytest.raises(ValueError, match="not found"):
+    apply_to_android._validate_android_path(_testdata_dir())
+
+
+def test_apply_to_good_dir():
+  apply_to_android._validate_android_path(_fake_android_dir())
diff --git a/tests/noto_fonts_for_android_test.py b/tests/noto_fonts_for_android_test.py
index 017507c71..bcfd84522 100644
--- a/tests/noto_fonts_for_android_test.py
+++ b/tests/noto_fonts_for_android_test.py
@@ -22,7 +22,7 @@ def _repo_root() -> Path:
 
 
 def _noto_4_android_file() -> Path:
-  xml_file = _repo_root() / "android-connection" / "noto-fonts-4-android.xml"
+  xml_file = _repo_root() / "android_connection" / "noto-fonts-4-android.xml"
   if not xml_file.is_file():
     raise IOError(f"No file {xml_file}")
   return xml_file
diff --git a/tests/testdata/fake_android/external/noto-fonts/fonts.mk b/tests/testdata/fake_android/external/noto-fonts/fonts.mk
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/testdata/fake_android/frameworks/base/data/fonts/fonts.xml b/tests/testdata/fake_android/frameworks/base/data/fonts/fonts.xml
new file mode 100644
index 000000000..e69de29bb